water leak

You can't see where it is leaking from since it is loosing so much coolant? And I at this point would suspect what ever "O" rings that were replaced. "O" rings go into aluminum mating parts and so due to heat, the surfaces may be warped, or from improper torquing of the bolts. Also check the water pump, there is a weep hole manufactured into it that when the seal goes bad, coolant would leak from.

Did you check the crossover tubes for cracks when you changed the rings & clamps?